A composite formed of various components has been issued a patent. The first component includes oxidized form thin film particles that are obtained by oxidizing graphite. The particles have a carbon skeleton, a thickness of 0.4 nm to 10 nm and a planar-direction size of at least 20 nm. They are dispersible in a liquid with a relative dielectric constant of at least 15. The second component includes reduced form thin film particles obtained by partially or completely reducing the first thin film particles so as to have an oxygen content of 0-35 wt %. The third component features a macromolecule as a matrix component the fourth component includes low molecular-weight parts that bond the thin film particles by a covalent bond.